» SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



at Upernivik, Iceland, and Gjesvaer, Norway. From 1885 to 1895 the 

 pressure changes at Gjesvaer were opposed to those at Upernivik, 

 from 1900 to 1924 they were similar, and from 1925 to 1930 they were 



M M M I I ! I I I I I I I I I I I I I I I I I I M I I I I I II I I II I I 



Fig. 6. — (i) Smoothed annual means of pressure at Upernivik, latitude 73° N., 

 longitude 56° W. (2) Smoothed annual means of pressure at (ijesvaer, latitude 

 71° N., longitude 25° E. 



again opposed. This dil^'erence indicates a shift in position of a center 

 of action, which fact will be considered later in connection with its 

 relation to solar activity. 



SUN SPOTS AND WEATHER 



The world-wide correlation of weather changes stiggests some gen- 

 eral cause, most probably a change in solar activity. The relation of 

 weather to sun-spot changes has been a subject of investigation for 

 many years by independent research workers. The most recent re- 

 search is that of Schostakowitsch, a review of whose work appeared 

 in the Bulletin of the American Meteorological Society for March 

 1933. These various investigations have brought out very clearly 

 that when a mean of several years is taken in the Tropics, the pres- 

 sure averages lower, the rainfall and cloudiness higher, and the sur- 

 face temperatures lower near sun-spot maximum than near sun-spot 

 minimum. 



In order to illustrate this point, a mean is taken of the annual 

 departures of pressure at Quixeramobim and Antananarivo given in 

 table I, columns (4) and (5). This mean was corrected for trend 

 and plotted In figure 7 over the inverted sun-spot curve for the interval 

 1889 to 1930. The pressure curve is more variable than the sun-spot 

 curve and usually shows about four maxima, a, b, c, d, in each sun- 

 spot period. By smoothing out these secondary maxima by over- 

 lapping means of 5, the broken curve is obtained which is seen to run 



